One warm summer night in 1881, a scrawny, nervous man sat in his boarding house a few blocks from the White House. Outside his window, gaslights flickered and horses clopped over cobblestones, but Charles Guiteau barely noticed. For six weeks now, a divine inspiration had festered in his fevered brain. The president, God told Guiteau, had to be “removed.”

Since early June, the lunatic had stalked the president with gun in hand. Enraged at James Garfield for fracturing the Republican Party, convinced that the split would precipitate a second civil war, Guiteau pursued his prey with single-minded calculation. One Sunday he aimed at Garfield through a church window; the following Saturday he crouched in a train depot as the president walked past, but spared him out of pity for the ailing wife clinging to her husband’s arm. A few mornings later, the little man waited along the Potomac, where the president often rode. No horse passed. Now Guiteau could wait no longer, and he began a letter to be delivered the next day:

To Gen. Sherman:

I have just shot the President. I shot him several times as I wished him to go as easily as possible. His death was a political necessity. I am a lawyer, a theologian, and politician. . . . I am going to the jail. Please order out your troops and take possession of the jail at once.

Very respectfully,

Charles Guiteau

The following morning, July 2, President Garfield stepped from his carriage outside the Baltimore and Potomac depot at Sixth Street and Constitution Avenue. As he strolled past admirers, the president all but beamed. After weathering a season of political infighting, he was leaving Washington for the summer. Plans called for him to meet his wife at the Jersey shore, cruise the Hudson, attend his 25th college reunion at Williams College, and then spend August on a farm in Massachusetts. Chatting with his secretary of state, Garfield strode into the waiting room. Across the clutter of heads and hats, he spotted the Venezuelan minister. He had just returned the latter’s polite nod when he heard a shot and felt a stabbing pain in one arm.

“My God! What is this?” he cried. Another blast echoed; a second bullet caught him full in the back, and he pitched face down onto the marble floor.

Two names of presidential assassins are deeply etched in American memory: John Wilkes Booth and Lee Harvey Oswald. Fewer Americans today recall Leon Czolgosz, who shot President McKinley in 1901. The only other man to kill a U.S. president, though his name was once synonymous with villainy, has been forgotten. Yet for decades after Charles Guiteau went to the gallows singing “I am going to the Lordy,” his fate was debated in psychiatric journals, law schools, and the court of public opinion. For despite his confession and a Victorian propriety that considered mental illness a question of morality, “the assassin Guiteau” was tried on a defense of insanity.

In 1881 Sigmund Freud had just earned his medical degree in Vienna. Doctors who worked with the mentally ill were not called psychiatrists but “alienists,” a word derived from French usage. In late 19th-century America, alienists ran asylums where the “crack-brained” and “feeble-minded” raved through horror-ridden halls. Insanity was sometimes blamed on disease but more often on sin, self-indulgence, or “religious excitement.” Newspapers brought daily reports of the insane—a man driven mad by “over-study,” a teenage girl institutionalized after taking a freezing bath, a housewife suddenly eloping with a stranger. Patent medicines promised to cure “Seminal Weakness, Spermatorrhea, and many other diseases that lead to insanity.” Misconceptions about mental illness were reinforced by rigid Victorian moralism. And a criminal who pleaded insanity as a defense had to face the McNaughten Rules. Based on a British case from 1843, the rules required the defense to prove the accused “was laboring under such a deficit of reason, from disease of the mind, as not to know the nature and quality of the act he was doing.” A man who committed a crime, unless entirely out of touch with reality, had to suffer the consequences. The insanity defense, commonly called “the insanity dodge,” might be used in small-town murder cases; but could it palliate the assassination of the nation’s chief executive?

Toward 10 a.m. on July 2, pandemonium reigned in the Baltimore and Potomac depot. As the president lay gasping for breath amid a circle of onlookers, his assailant walked briskly through the bedlam, his .44 still smoking. Shouts filled the waiting room.

“There he goes!”

“Stop him! He shot the president!”

Guiteau scrambled for the door, but an alert policeman wrestled him to the ground. His eyes wild, his voice electric, the madman shouted, “Yes! I have killed Garfield! Arthur is president of the United States! I am a Stalwart! I have a letter that will tell you all about it. I want you to take it up to General Sherman.” Police marched him through gathering crowds calling out “Lynch! Lynch!” He was dragged off to jail, where other officers quickly noted his “loony” appearance.

The stricken president was taken upstairs and given brandy. Looming over him, his son sobbed. Secretary of War Robert Todd Lincoln, who just 16 years earlier had comforted his dying father, paced the room. The night before, he and Garfield had discussed the topic of assassination. “How many hours of sorrow I have passed in this town,” Lincoln said. (Twenty years later, Lincoln would witness his third presidential assassination when Czolgosz shot McKinley.) A doctor examined Garfield’s back, inserting fingers into the wound. The president grimaced. The doctor assured him he would recover. “I thank you, doctor,” Garfield replied, “but I am a dead man.” Across town, Gen. William Tecumseh Sherman read Guiteau’s letter and ordered the White House guarded against a larger plot.

The news of the shooting sent shock waves across Gilded Age America. From out west, where Indian wars still raged, to East Coast cities filling with both mansions and tenements, people took to the streets. By noon, when some newspapers reported Garfield’s death, bells tolled and crowds wept. But the president was clinging to life in the White House, as he would all summer.

Few knew much about the man who had been president for just four months, but Garfield’s biography seemed archetypal. Born in an Ohio log cabin, he had risen from one-room schoolhouses to a New England college, then to lay preaching, academia, and finally to Civil War battlefields. A veteran of Shiloh and Chickamauga, General Garfield was elected to Congress, where he survived Reconstruction’s infighting to emerge in 1880 as a Republican dark horse presidential candidate, winning the nomination on the 36th ballot. A strong debater, Garfield was known as bookish, a capable mathematician and classicist—he could simultaneously write with one hand in Greek, the other in Latin—and serious to the point of appearing boring. But the country now rallied behind him, hailing Garfield as “one of the greatest presidents ever chosen” and freely comparing him to Lincoln. Who would want to kill such a man?

The next morning, newspapers began detailing Charles Guiteau’s tawdry life. Raised in rural Illinois, he had been an irascible child, frequently beaten, scarred by his mother’s death, and abandoned when his father remarried. Unable to make friends, Guiteau had sought solace in the Oneida Community, an upstate New York commune notorious for free love and “Bible communism,” but he quarreled with his coreligionists and left in a rage. Adrift in Reconstruction-era America, he finally settled in Chicago, where he began giving religious lectures. Ranting about “the kingdom of God on earth,” Guiteau quickly earned a reputation as a “crank,” an “unendurable nuisance,” and a “knave of the darkest character.” Hadn’t he once threatened his sister with an ax? Some knew him as a “crack-brained” lawyer who thundered in court, others as a swindler who cheated merchants and skipped out on hotel bills. “There is no man who has had anything to do with Guiteau for years past but knows him to be insane,” a prominent attorney told a reporter. Since March, the nation learned, Guiteau had been in Washington, pestering the White House and the State Department to name him American consul to Paris. “Disgruntled office seeker” was how history would explain Guiteau’s crime, but throughout July it remained only an “attempted assassination.”

As Garfield’s condition stabilized, his pulse and respiration were reported daily in the press. Meanwhile, Americans eagerly anticipated the trial of “the assassin Guiteau.” Interviewed in his cell, he insisted that “the Deity” had inspired him, and that when Americans realized he had averted another civil war he would be welcomed as a hero on the lecture circuit. Then came the outrageous news that Guiteau might try “the insanity dodge.” A writer for the New York Times quipped, “The feeling is quite general that it would be best to execute him first and try the question of his sanity afterward.”

Come August, doctors were predicting Garfield’s recovery. But the “lost bullet” lodged near his liver combined with the steam heat of the nation’s capital to keep the president hovering between life and death. On August 2 Alexander Graham Bell came to the White House with a primitive metal detector he had built to find the bullet. When this device failed—Bell did not know that the bed contained metal springs—doctors again probed Garfield’s back wound. Current medical opinion holds that Garfield should have recovered from his wounds, but in an age when the “germ theory” of disease was only beginning to be accepted, surgeons continued to probe with unsterilized fingers. Sepsis soon set in. By September, the president was in critical condition, and the nation seethed with vengeance.

On September 4 a mob in Buffalo burned Guiteau in effigy. A week later, a guard disgusted at having to protect “such a cur as Guiteau” fired into his cell, the bullet grazing the assassin’s head. A few days later, another guard attacked Guiteau with a knife, but the inmate’s screams brought help. Ten days later, the president, taken to the Jersey shore to escape the heat, awoke late in the evening. “How it hurts here!” Garfield said, clutching his heart. On September 19, with his grieving wife by his side, he died.

Within minutes, bells tolled in every American city. Guiteau trembled in his cell, asking guards whether a mob might be outside, cowering when they made the slightest move toward him. Within a week, he was indicted. A speedy trial was promised, but the public had already come to its verdict.

Much of the evidence for Guiteau’s guilt was based on his early October jailhouse “autobiography,” in which he had explained how, on a restless night in his boarding house, “the idea [had] flashed through my brain that if the president was out of the way, everything would go better.” He painstakingly recounted how he bought his gun, fired it on the banks of the Potomac, and then stalked the president. His narrative made the assassination seem the work of a calculating criminal, yet Guiteau soon began to show America otherwise.

From the moment the trial convened, Guiteau commanded the courtroom. Denouncing his lawyers, shouting at the judge, and exploding into religious rants, the defendant appalled and fascinated the overflow gallery. His misshapen head, closely cropped hair, and flaring eyes were equally alarming.

“Looks crazy,” said one spectator.

“Ain’t got the brains to be crazy.”

When not raving, Guiteau sat penning a long speech comparing himself to Washington and Grant and insisting that he would soon be known as “Guiteau, the patriot.” While he wrote, the prosecution mounted its case.

Witnesses tearfully recalled how sudden shots and chaos broke the stillness of the morning of July 2 as the president strode into the depot. At the defense table, Guiteau seethed. Whenever testimony veered from his version, he responded with rage—“I wore my hat in the usual way! I do not go sneaking about! I do things on the square!” Siblings tried to calm him, but Guiteau turned on them: “Oh, mind your business! Let me alone. I am lead counsel and will talk just as much as I want to!” Fearing a mistrial, the judge refused to silence Guiteau.

With a bizarre defendant and witnesses including General Sherman and several senators, the trial became the capital’s event of the season. Each morning, long lines formed outside the courthouse. Guiteau’s arrival brought hisses, while any talk of insanity bred outrage. “We don’t want any cursed foolishness in this trial and we won’t have any,” a Civil War veteran told the Washington Post. “If they play malpractice and insanity the case will end damned soon.”

On the trial’s fifth day, vengeance boiled over. That day in court, a preserved section of the president’s spine was passed from witness to jurors, each examining the bullet hole. When the ghastly object was handed to Guiteau, the gallery fell silent. For once, he said nothing. That afternoon, as he rode back to the jail in a police van, a man on horseback pulled alongside, raised a revolver, and fired. “Oh, I am shot!” Guiteau screamed, falling to the floor. Back in his cell, he nursed a bruise on his arm where the bullet had glanced off. When heckled through the bars of his cell, he shouted back: “People will learn after awhile that the Lord is with me and will not allow me to be killed!” The next day, the prosecution rested its case.

On November 24, 1881, rising to his brother-in-law’s defense, attorney George Scoville faced a daunting task. According to the McNaughten Rules, Scoville had to prove that Guiteau was so deranged that he did not know he was doing what was wrong. The insanity defense had been used frequently in recent years, yet rarely in a capital case, and only once in the trial of a would-be assassin. In 1835 a deranged man had taken aim at President Andrew Jackson, but his pistols had misfired. Attorney Francis Scott Key, who wrote “The Star-Spangled Banner,” prosecuted the assailant, who pleaded insanity—claiming to be King Richard III—and was institutionalized for life. But Jackson had been unharmed; Garfield had not been so lucky, and neither would his assassin.

Various commentators had already weighed in on Guiteau’s mental condition. “There’s nothing of the madman about Guiteau,” declared District of Columbia district attorney George Corkhill. “He’s a cool calculating blackguard, a polished ruffian, who has gradually prepared himself to pose in this way before the world.” The American Law Review added, “The danger to society from an insane murderer is at least as great as from a sane murderer . . . Let us destroy an insane murderer as we do anyone or anything else whose continued existence threatens the general safety.” Even alienists seemed to be against Guiteau. The most common causes of insanity, according to a census of asylums, were masturbation, intemperance, and ill health. Guiteau’s lawyer would have to challenge an entire culture’s conventional wisdom. Scoville reminded the jury of society’s increasing empathy with the insane, then summoned an impressive array of witnesses.

One told the court of Guiteau’s ax assault on his sister; others recounted how his fanatical father had practiced faith healing and claimed he would live forever. Another described one of Guiteau’s lectures, cut short when the “theologian” stormed off the podium: “After he went out, we had a conference and all came to the conclusion that he was crazy.” After Guiteau’s sister testified that he had “clear gone daft,” the defense called its most compelling witness: the defendant himself.

Stepping onto the stand, Guiteau riveted the courtroom. Pale, quivering, his eyes darting, he told of his brutal childhood, then read from his self-published religious pamphlet. As he spoke, 20 alienists sat nearby, taking notes: one later said Guiteau was the most fascinating psychotic he had ever seen. In the gallery, a tall, white-haired African American offered his opinion. “If it is acting,” Frederick Douglass judged, “he is the most consummate actor in the world.”

Guiteau testified for five days, explaining how God had ordered him to kill the president: “The idea kept working me and working me and grinding and oppressing me.” He had prayed for a sign that “the idea” wasn’t what it seemed, but none came. He had been chosen, he concluded, “because I had the brains and the nerve to do the work and because the Deity always chooses His best material to do His work.”

Rising to cross-examine, prosecutors turned to their most potent weapon—ridicule. When Guiteau again invoked his divine inspiration, they were ready.

“Who bought the pistol, the Deity or you?”

“I said the Deity inspired the act, and the Deity would take care of it.”

“The question is, ‘Who bought the pistol?’”

“The Deity furnished the money with which I bought the pistol. I was the agent.”

“Do you believe in the Ten Commandments?”

“Yes.”

“Have you higher evidence that the Supreme Ruler of the Universe said to you, ‘Thou shalt kill’ than you have that he said, ‘Thou shalt not kill?’”

On his final day in the dock, Guiteau admitted he had hoped that the assassination would increase sales of his pamphlet. He called himself “a man of destiny as much as the Savior or Paul or Martin Luther.” Finally, the prosecutor put the crucial question.

“Are you insane at all?”

“A good many people think I am badly insane. The Oneida people thought so, my father thought so, and my relatives thought so and still think so.”

“You told the jury you were not insane.”

“I am not an expert. Let the experts and the jury decide whether I am insane.”

Onlookers agreed that Guiteau was alarming, terrifying, indeed fascinating. But was he criminally insane? As the trial inched toward a new year, the question consumed the nation. Tourists flocked to Washington, hoping for a glimpse of Guiteau, “as if he were some rare wild animal,” noted the Washington Post. Other newspapers denounced Guiteau as an “impostor” and the chaotic trial as “a burning shame.” The nation’s most famous clergyman, Henry Ward Beecher, judged Guiteau “sane enough to hang,” and added, “I am not especially in favor of hanging but if ever there was a case for it, there is one now.” Was “the assassin,” “the coward,” the “miserable scoundrel,” an actor or a lunatic? It was time for expert opinion.

In its final days the trial pitted the 19th century against the 20th. For two weeks alienists struggled to define insanity. Was it hereditary? Yes, said defense experts, pointing to Guiteau’s father and an uncle in an asylum. Prosecution experts disagreed. Like any disease, they insisted, insanity had an onset and a deeper development, yet Guiteau’s eccentricities were consistent throughout his life. But did insanity manifest itself in physical deformity? Yes, said defense experts. Guiteau agreed. “That hits my case exactly!” he shouted. “One side of my head is larger than the other. Doctors examined me the other night!” Finally, was there such a thing as “moral insanity”?

“I believe in moral insanity,” replied Dr. James G. Kiernan, a Chicago-based physician and staunch critic of asylums and their treatment of the insane.

“You believe that the mind of a man may not be diseased and yet his moral nature may be diseased?”

“Yes, in certain rare cases.”

Prosecution experts rose in righteous indignation. The causes of insanity were many—“over-worry, hard work, insufficient food, venereal diseases”—but the chief cause was, “Intemperance, Sir!” As for “moral insanity,” the very idea was denounced by Dr. John Gray, editor of The American Journal of Insanity. Moral insanity, the staunchly Victorian doctor told the court, “is wickedness, a term loosely used to excuse or palliate conduct, which on any other theory is indefensible.” Likewise, Gray added, other so-called mental disorders—kleptomania, dipsomania, pyromania—were excuses, “make-shifts to secure from punishment for crime.”

Insane? The prosecution preferred other terms: “A shrewd scamp” perpetrating a “desperate scheme.” The defense fought back: “unquestionably insane”; “a moral imbecile,” “as insane as any inmate of any asylum I ever saw.” Guiteau added his own evidence, predicting “an act of God that will blow this court and the jury out that window to protect me if necessary!” After another tirade, public opinion mustered itself in the gallery: “Shoot him now!”

On January 25, 1882, after ten fraught weeks, nearly 100 witnesses, three attempts to murder the defendant, and Guiteau’s continued ravings, America’s first prosecution of a presidential assassin went to the jury. Outside, the late afternoon light was fading. The judge read the final instructions by candlelight. The jury retired.

“Perhaps they will hang me,” Guiteau told a guard, “but the Deity will disappoint them.”

Twenty minutes later, the jury returned. Ghostly shadows flickered on the wall as the verdict was read: “Guilty.” The gallery erupted in cheers. Guiteau shouted, “My blood will be on the heads of that jury!” Led away in handcuffs, he asked, “How does the verdict strike those people outside?”

The verdict was telegraphed across the nation, posted outside newspaper offices, and shouted from theater balconies. Spontaneous parades broke out. The press rejoiced. “the hyena hangs!” (Chicago Tribune). “the comedy is played out !” (New Orleans Bee). At his sentencing, Guiteau denounced his brother-in-law’s “jackass theory” of insanity and warned, “The American nation will roll in blood if my body goes into the ground!” He was sentenced to hang on June 30.

Over the next few months, several alienists petitioned President Chester Arthur to appoint an independent board to examine Guiteau, but the president refused. A new trial was denied. In June three alienists went to the White House to seek clemency. The president asked his attorney general for a ruling. The verdict stood.

At noon on June 30, Guiteau mounted the scaffold in the same jail where he had been held since the shooting. Outside hundreds mingled, buying lemonade and cake. In the jail’s courtyard, nearly 250 people, some having paid $300 for the privilege, gazed at the gallows. Guiteau cast his eyes over them and chanted: “I am going to the Lordy, I am so glad / I am going to the Lordy, I am so glad.”

When he had finished, a black hood was put over his head. He shouted, “Glory, ready, go!” and fell through the trap.

Bitter dispute over “the assassin Guiteau” lingered, but the autopsy shifted the debate. Guiteau’s brain showed signs of syphilitic paresis, asymmetry of the right and left hemispheres, and a chronic degeneration of gray matter. By the 1890s several psychiatric journals that had once challenged his insanity had changed their opinions. Come the century of Freud, and the definition of insanity broadened. In 1912 a deranged drifter who shot Theodore Roosevelt was institutionalized without trial. By the 1920s, psychiatrists agreed that Charles Guiteau had been mad, his trial a travesty, his execution shocking.

In 1982, a century after Guiteau’s execution, Ronald Reagan’s assailant, John Hinckley Jr., was held “not guilty” by reason of insanity, a verdict that brought nationwide outrage and a tightening of insanity defense laws. Yet history’s ultimate verdict on Charles Guiteau remains unchanged. Had he shot a common man, he would have been institutionalized after no more than a hearing. And had President Garfield lived, his assailant would have also been spared as being, pure and simple, a lunatic.

The insanity defense remains a delicate issue in American jurisprudence. Since Guiteau, numerous legal terms have arisen to qualify the plea. Did the defendant demonstrate “diminished capacity,” or “criminal responsibility”? Several states have devised a compromise verdict: “guilty but mentally insane.” Still, the struggle between morals and mental illness, between the law and psychiatry, continues.

Earlier this year, when alleged Tucson assailant Jared Lee Loughner pleaded not guilty to wounding Representative Gabrielle Giffords and killing six others, pundits broached the possibility that he might be freed on an insanity plea. Legal experts agreed that, given the assassination attempt’s high profile and the defendant’s premeditation, an insanity defense would be a long shot. But the outrage expressed by many showed that America’s staunch insistence on criminal responsibility did not die with the Victorian age. Is the insanity plea “a dodge” or an act of mercy? The jury is still out.